Helleborus plant named ‘HGC Silvermoon’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘HGC Silvermoon’, characterized by its compact and mounded plant habit; dark green-colored leaves; and white to light green-colored flowers.

Botanical classification/cultivar designation: Helleborus niger×H.sternii cultivar HGC Silvermoon.

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus niger×H. sternii, andhereinafter referred to by the cultivar name HGC Silvermoon.

The new Helleborus is a product of a planned breeding program conductedby the Inventor in Glandorf, Germany. The objective of the breedingprogram was to create new Helleborus cultivars with a good plant habit,that flower for a long period of time, and have attractive flowercoloration.

The new Helleborus originated from a cross-pollination made by theInventor in January, 1999 in Glandorf, Germany of an unnamed seedling ofHelleborus niger, not patented, as the female, or seed, parent with anunnamed seedling of Helleborus sternii, not patented, as the male, orpollen, parent. The new Helleborus was discovered and selected by theInventor as a flowering plant within the progeny of the statedcross-pollination in a controlled environment in Glandorf, Germany.

Asexual reproduction of the new cultivar by divisions at Glandorf,Germany since March, 2001, has shown that the unique features of thisnew Helleborus are stable and reproduced true to type in successivegenerations.

SUMMARY OF THE INVENTION

Plants of the cultivar HGC Silvermoon have not been observed under allpossible environmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature and light level without,however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘HGC Silvermoon’. These characteristicsin combination distinguish ‘HGC Silvermoon’ as a new and distinctcultivar of Helleborus:

-   -   1. Compact and mounded plant habit.    -   2. Dark green-colored leaves.    -   3. White to light green-colored flowers.

Plants of the new Helleborus flower about two months later than plantsof the female parent. In addition, plants of the new Helleborus andfemale parent differ in flower coloration. Compared to plants of themale parent, plants of the new Helleborus have less leaf serration andflower about one month earlier.

Plants of the new Helleborus can be compared to the Helleborus nigercultivar HGC Jericho, disclosed in U.S. Plant patent application Ser.No. 10/878,420. In side-by-side comparisons conducted in Glandorf,Germany, plants of the new Helleborus differed from plants of thecultivar HGC Jericho in the following characteristics:

-   -   1. Plants of the new Helleborus had longer leaf petioles than        plants of the cultivar HGC Jericho.    -   2. Plants of the new Helleborus had flatter flowers than plants        of the cultivar HGC Jericho.    -   3. Plants of the new Helleborus and the cultivar HGC Jericho        differed in flower coloration.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new cultivar, showing the colors as true as it is reasonablypossible to obtain in colored reproductions of this type. Colors in thephotographs may differ slightly from the color values cited in thedetailed botanical description which accurately describe the actualcolors of the new Helleborus.

The photograph at the top of the sheet comprises a side perspective viewof a typical flowering plant of ‘HGC Silvermoon’.

The photograph at the bottom of the sheet is a close-up view of atypical flower of ‘HGC Silvermoon’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs, following observations and measurementsdescribe plants grown in Glandorf, Germany, in a glass-coveredgreenhouse and under commercial production practices during the winter.Plants were grown in 15-cm containers and were about six months old whenthe photographs and description were taken. During the production of theplants, day temperatures were about 18° C. and night temperatures wereabout 14° C. In the following description, color references are made toThe Royal Horticultural Society Colour Chart, 1995 Edition, except wheregeneral terms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus niger×H. sternii cultivar HGC    Silvermoon.-   Parentage:    -   -   Female parent.—Unnamed seedling of Helleborus niger, not            patented.        -   Male parent.—Unnamed seedling of Helleborus sternii, not            patented.-   Propagation:    -   -   Type.—By divisions.        -   Time to initiate roots, winter.—About 40 days at 12° C.        -   Time to produce a rooted plant, winter.—About six months at            12 to 15° C.        -   Root description.—About 3 to 15 thick fleshy roots; not            branching; white to brown in color.-   Plant description:    -   -   Plant form/habit.—Compact and mounded plant habit;            moderately vigorous growth habit. Leaves basal. Single            flower form.        -   Plant height.—About 14 cm.        -   Plant width (spread).—About 30 cm.        -   Foliage description.—Arrangement: Basal; palmately compound            with three to five leaflets per leaf. Leaflet length: About            5 to 10 cm. Leaflet width: About 2.5 to 4 cm. Leaflet shape:            Lanceolate; pedate. Leaflet apex: Apiculate. Leaflet base:            Acute. Leaflet margin: Serrate. Texture, upper and lower            surfaces: Smooth, glabrous. Venation pattern: Reticulate.            Color: Developing leaflets, upper surface: 137A. Developing            leaflets, lower surface: 147B. Fully expanded leaflets,            upper surface: 147A. Fully expanded leaflets, lower surface:            147B. Venation, upper surface: 146B. Venation, lower            surface: 183A. Petiole: Length: About 8 cm. Diameter: About            4 mm. Texture, upper and lower surfaces: Smooth, glabrous.            Color, upper and lower surfaces: 183A.-   Flower description:    -   -   Flower type/habit.—Single rounded flowers arranged singly on            upright peduncles; flowers face upright to outwardly; petals            inconspicuous. Freely flowering habit with about 10 flowers            developing per plant over the flowering period.        -   Fragrance.—Slightly fragrant.        -   Natural flowering season.—Intermittent flowering from            December to February in Glandorf, Germany. Flowers            persistent.        -   Postproduction longevity.—Flowers last about ten days on the            plant.        -   Flower buds.—Height: About 1.2 cm. Diameter: About 7 mm.            Shape: Ovoid. Color: 145D.        -   Flowers.—Diameter: About 7 cm. Depth: About 1.5 cm.        -   Petals.—Size: Minute, obscured by reproductive organs;            forming inconspicuous nectaries.        -   Sepals.—Quantity/arrangement per flower: Typically five in a            single whorl. Length: About 3.5 cm. Width: About 3 cm.            Shape: Broadly ovate. Apex: Rounded. Margin: Entire.            Texture, upper and lower surfaces: Smooth, glabrous; satiny.            Color: Developing sepals, upper surface: 155A. Developing            sepals, lower surface: 155A slightly overlain with 60A.            Fully expanded sepals, upper surface: 149D. Color becoming            closer to 145B to 145C with development. Fully expanded            sepals, lower surface: 149D slightly overlain with 187A.        -   Peduncles.—Length: About 5 to 7 cm. Diameter: About 3 to            5 mm. Orientation: Upright. Strength: Strong. Texture:            Smooth, glabrous. Color: 145A overlain with 185A. Pedicels:            None.        -   Reproductive organs.—Stamens: Quantity per flower: About 70.            Anther shape: Oblong. Anther length: About 3 mm. Anther            color: 154C. Pollen amount: None observed. Pistils: Quantity            per flower: About five. Pistil length: About 2 cm. Stigma            shape: Tuberculate. Stigma color: 145C. Style length: About            1.1 cm. Style color: 145C. Ovary color: 145B.        -   Seed/fruit.—Seed and fruit development have not been            observed.-   Disease/pest resistance: Plants of the new Helleborus have not been    noted to be resistant to pathogens and pests common to Helleborus.-   Temperature tolerance: Plants of the new Helleborus have been    observed to tolerate temperatures from −10 to 36° C.

1. A new and distinct cultivar of Helleborus plant named ‘HGCSilvermoon’, as illustrated and described.